Marsh Funnel testing for rheology analysis of bentonite slurries for Slurry Shields

Abstract: For the face support during slurry shield tunnelling, the rheology of the bentonite suspension has to meet strict requirements. Determination of the rheological properties follows the international standards API 13B [1] and DIN 4126 [2]. On the construction site, simple and robust measurement methods are required for quality control of the suspension parameters during the tunnelling process. Here, the Marsh-funnel is commonly accepted as a useful and reliable measuring device. The Marsh-time is recorded in [s] for a certain suspension volume. Based on this “single point measurements” only relative conclusions are derived concerning the viscosity of the bentonite suspension.